A revisit to the region of Collinder 132 using Carte du Ciel and Astrographic Catalogue plates

Aims. Based on stellar positions and proper motions, we aim to re-analyse the region of the controversial open cluster Collinder 132. Methods. We have developed a model which analyses the proper motion distribution and the stellar density to find moving groups. The astrometric data were obtained from four Carte du Ciel (CdC) and one Astrogaphic Catalogue (AC) plates of the Córdoba Astronomical Observatory collection (Argentina). Results. We detected an open cluster from the field stars and calculated the mean proper motion and the membership probabilities of the region's stars. We report new coordinates of its centre αc = 108\fdg347, δc = -31\fdg011, the components of mean proper motion μ αcosδ = -2.62±0.44 mas/yr, μδ = 4.79±0.88 mas/yr. Thirteen stars are astrometric members giving a value of 20' for the cluster angular diameter. Six stars fulfil the astrometric and photometric criteria for being cluster members and locate the cluster at 360 pc from the Sun. We propose a simple model for the analysis of the proper motion distribution of an association. We report the components of the association mean proper motion μαcosδ = -1.38±0.14 mas/yr, μδ = 2.26±0.16 mas/yr. We found 149 astrometric members, 11 of which have reliable photometric data that locate them betweeen 417 and 660 pc from the Sun.Este documento tiene una corrección (ver documento relacionado).Instituto de Astrofísica de La PlataFacultad de Ciencias Astronómicas y Geofísica

SOLANUM LYCOPERSICUM X S. PENNELLII INTROGRESSION LINES WERE USEFUL TO CHARACTERISE THE IONOME OF TOMATO FRUIT

In the frame of "GenoPom" PON-MIUR project, we have began a study of tomato ionome in order to identify the contribution of specific chromosome and part of them on the ionome. For this purpose, we have analysed by ICP-MS plants of an introgression line (IL) population derived from the cross between Solanum lycopersicum cv. M82 and S. pennellii (Eshed and Zamir, 1995) grown under controlled environmental conditions.we report results derived from tomato whole fruits ionome analysis of 30 IL, covering all 12 tomato chromosomes, along with the recurrent parent cv. M82. Among several detected elements, the following ones have firstly been analysed: Ca, Fe, Cu, Zn and Se. Each element concentration data were referred to cv. M82

Approach combining the Rietveld method and pairs distribution function analysis to study crystalline materials under high-pressure and/or temperature: Application to rhombohedral Bi2Te3 phase

An approach combining the Rietveld method and pairs distribution function analysis to study crystalline materials under high pressure or temperature was early proposed by us, and in this study, it was applied to investigate de effect of high pressure on the rhombohedral Bi2Te3 phase. The refined structural parameters obtained from the Rietveld refinement of the XRD patterns measured for pressures up to 9.1 GPa were used as input data to simulate the partial and total structure factors SBiBi, SBiTe, STeTe, and SBi2Te3. Fourier transformation of the Sij factors permitted to obtain the partial and total pairs distribution functions GBiBi, GBiTe, GTeTe, and GBi2Te3. The first coordination shells of these Gij functions are formed by subshells and, with increasing pressure in the 1.1 to 6.3 GPa range, occur a partial separation of subshells. Also, the increase of pressure in this range promotes a drastic reduction in the values of the intralayer angles TeBiTe, and consequently, in the intralayer distance TeTe. A drastic reduction in the interlayers distance Te-Te was also observed. Several studies are reported in the literature, including one carried out by us, show the presence of an ETT in this pressure range. The obtained results suggest that the ETT is related with the decrease of the intralayer angles TeBiTe, and intra- and interlayer distance TeTe. Experimental results describing the pressure dependence the thermoelectric power, electrical resistivity, and power fator for rhombohedral Bi2Te3 are reported, and an enhancement of the power factor in the 1.1 to 6.3 GPa range is observed. The results obtained in this study give evidence that this enhancement in the power factor is related with the decrease of the intralayer angles TeBiTe, and with the decrease of intralayer- and interlayers homopolar TeTe bonds

A revisit to the regions of some van den Bergh open clusters using photometric and astrometric parameters

We present results of a study that combines photometry and astrometry for the open clusters vdB80, vdB85 and vdB130. We apply a model which analyses the proper motion distribution and the stellar density to find the kinematic parameters and stellar membership in the region of the mentioned open clusters. The astrometric data are obtained from UCAC4 catalogue. For each cluster, we report the centre coordinates, the components of mean proper motion, the angular diameter and the astrometric members. They are: α=97°.73938±0°.00846,δ=-9°.66953±0°.01177,μαcosδ=-2.13±0.47mas/yr,μδ=-0.95±0.47mas/yr,12′ , 15 members; vdB85: α=101°.71670±0°.00808,δ=1°.34392±0°.01253,μαcosδ=0.89±0.43mas/yr,μδ=3.24±0.43mas/yr,8′ members; vdB130: α=304°.44001±0°.01407,δ=39°.32745±0°.00726,μαcosδ=-4.14±0.25mas/yr,μδ=-5.15±0.25mas/yr,9′ 9 members. We analyse the incidence of the proper motion errors in the determination of the cluster parameters and of the stellar membership and find that they are not significantly changed. We finally compare the astrometric members with the photometric ones given in the literature.Instituto de Astrofísica de La PlataFacultad de Ciencias Astronómicas y Geofísica

LiCaFeF6 A zero strain cathode material for use in Li ion batteries

A new zero strain LiCaFeF6 cathode material for reversible insertion and extraction of lithium ions is presented. LiCaFeF6 is synthesized by a solid state reaction and processed to a conductive electrode composite via high energy ball milling. In the first cycle, a discharge capacity of 112 mAh g amp; 8315; is achieved in the voltage range from 2.0 V to 4.5 V. The electrochemically active redox couple is Fe3 amp; 8314; Fe2 amp; 8314; as confirmed by Mössbauer spectroscopy and X ray absorption spectroscopy. The compound has a trigonal colquiriite type crystal structure space group . By means of in situ and ex situ XRD as well as X ray absorption fine structure spectroscopy a reversible response to Li uptake release is found. For an uptake of 0.8 mol Li per formula unit only minimal changes occur in the lattice parameters causing a total change in unit cell volume of less than 0.5 . The spatial distribution of cations in the crystal structure as well as the linkage between their corresponding fluorine octahedra is responsible for this very small structural response. With its zero strain behaviour this material is expected to exhibit only negligible mechanical degradation. It may be used as a cathode material in future lithium ion batteries with strongly improved safety and cycle lif